Connect with TRB

ANALYSIS OF FATAL ACCIDENT TRENDS ON MARYLAND HIGHWAYS, 1970-1976

Various multivariate regression analysis techniques were used to analyze 7 years of fatal automobile accident and accident rate data for highways affected by the 89 km/h speed limit law in Maryland. Four of the fifteen variables studied -- the normal historical decline in fatal accident rates with time, changes in the posted speed limit, changes in the level of traffic volume, and increases in police enforcement -- statistically contribute to the explanation of the raw variance in the number and rate of fatal accidents. These four variables account for more than two-thirds of the total variance. Techniques for analyzing data from these highly intercorrelated variables are discussed and employed.